Switch mechanism



Feb. s, 1934,

v. G. APPLE. 1,945,720

SWITCH MECHANISM 2 Sheets-Sheet v 1 Filed Jan. 2s, 195o l N VEN TOR.

BY v 4 @fm2/Pr@ A TTORNEY Feb. 6, 1934. v, Q APPL 1,945,720

SWITCH MECHANISM Filed Jan. 23. 1930 2 Sheets-Sheet 2 N VEN TOR. Mncem.L Q .x7/Pie A TTORNEYS Patented Feb. e, 1934 y 1,945,720,

UNITED STATES PATENT OFFICE SWITCH MECHANISM Vincent G. Apple, Dayton, Ohio, assignor to Bendix Brake Company, South Bend, Ind., a' corporation of Illinois Application January 23, 1930. Serial No. 422,747 4 Claims. (Cl. 20o-83) My invention relates to electric switches and ing means therefor, and also provides an annular has particular reference to that type of switch seat for the ring 22, which latter acts in conwherein the member which bridges the contacts junctionv with the plate 20 to insure the proper is controlled by the movement of a pressure diadegree of tautness in the diaphragm membrane.

phragm, l A second plate member 24, which is composed of 60 An object of my invention is to provide a presany desirable ilexible material, preferably fabrisure diaphragm switch which may be utilized to cated, is seated on the diaphragm 18 and secured control the circuit which drives an air comin that position by means of the ring 22. This ii pressor. I contemplate utilizing the air comsecond plate member 24 is provided with a cen- 1 pressor for some such purpose as maintaining tral aperture whereby it is secured to the plunger 65 adequate pressure in a compression tank for op- 26. The plate is provided with a central apererating brake mechanism on an automotive veture through which the plunger 26 extends, and mele, this plunger is provided with a plate 28 at its A particular object of my invention is to so upper extremity which serves as a bearing for the design this pressure operated switch that it will inner ends of the rocker arms 30. A plurality of 70 permit the pressure bearing against the diastuds 32 are secured to the upperside of the phragm member thereof to Vary within a certain plate member 20 and these stud members serve as predetermined Irange without functioning to supports for pivoting the said rocker members 30. close the switch and so start the compressor. Each of the stud members 32 is provided with an 20 Still a further ob'ject of my invention is to pro-A upwardly extending ange 34 on the outer side 75 vide a very simple, compact, and eiicient switch of its upper extremity, landthese anges form a of high current carrying capacity which may `be positive seat for the plate member 36. The coil easily mounted on. any electrical or automotive spring 38 is seated on this plate member 36 and apparatus, its upper extremity bears against another plate Still other objects and meritorious features member 40, which is cup shaped as indicated in 30 will become apparent from the following de- Figs. 1 and 2, so that it may `seat within the scription taken in conjunction withv the drawupper end of thecoil spring 38.

ings wherein like numerals refer to like parts A casing 42 is seated upon a peripheral flange throughout the several figures and wherein: 0n the plate 20 and bolts 44 are threaded through Fig. 1 isa sectional elevation of my improved the base, plate member 20, and upper portion of 85 mechanism, the casing for the purpose of retaining the various Fig. 2 is a similar view wherein the switch units together. Secured to the upper DOIJOn 0f is in open position, the casing in the form of a unit, held together and Fig. 3 is a plan viewof the reinforcing plate insulated from one another bythe spaced asseml utilized in conjunction with my pressure diably generally indicated by 46, are the two con- 90 phragm, tact members 48. An aperture is provided in the e., Fig. 4 is a section on the line 4-4 of Fig. 1, JOD 0f the Casing 42 through which extends a Fig. 5 is a plan view of my switch member, plunger 50. This plunger is seated in a central Fig. 6 is a fragmentary View, partly in section, aperture in the cup of plate 40, and provided with illustrating the manner in which my switch casa ange at its IOWBTIHOS extremity OI the D111- 95 ing is hem together, and pose of seating a spring 52. At its upper ex- Fig. '7 is a detailed view of one of the side rocktremty this Spring 52 bears against the underer arm members utilized to actuate the switch Side 0f CaSng 42- SeCUIed t0 the upper end Of bridge member. the plunger 50 is the bridge 54.

45 Numeral l0 indicates the supporting base for AS Clearly illustrated in Fig 1 and 2 each 0f 100 my switch assembly. It is provided with aperthe rocker members 30 is pivoted at its central tures 12 for the purpose of securing it to any con- Point and DIOVided 0n its inner end with a roller venient support. At one side thereof there is member 55- Each rocker member 30 iS pVOted aconduit 14 whichis for the purpose of Connectat its Central point and provided on its outer ing the pressure chamber 16, formed in the base, extremity With a Cammng S101? 53 n'O Which a 105 4 Withrsome reserve Supply of pressure such as a, pill GD. the lOWel' extremity 0f link 60 S inserted. pressure tank. seatedon the base member 10 The upper end 0f each 0f these links is pivoted and stretched across the chamber 16 is the diato the periphery of plate 40. phragm 18. This diaphragm is secured in place The operation of my pressure switch will be by means of plate 20 which functions as a clamp- Obvious. from the foregoing description, but will 110 be briey outlined herein. The spring members 38 and 52 are so balanced that the resultant of their pressure will normally retain the bridge member 54 in contact with the contact members 48. and thus close the electric circuit. This position of the members is illustrated in Fig. 1 of the drawings. When the pressure in the pressure chamber 16 has reached a predetermined minimum, as illustrated by the showing of Fig. 1, the resultant of the pressures of the springs will have closed the contacts. started an electric circuit through the compressor member, and thus startir'ig the building up of maximum pressure in the storage tank. As soon as this maximum pressure in the storage tank has been obtained. it will be transferred to the pressure chamber 16 of the switch. thus raising the diaphragm member 18. The plunger 26 which is constrained to move in accordance with the diaphragm member will raise the plate 28 and thus raise the inner end of the rocker member 30. This movement oi the rocker member 30 will cause a corresponding downward movement of the outer ends of the rocker member, thus drawing down the bridge member 54, utilizing the combined pressure exerted against the diaphragm i8 and the advantageous camming surface of the slot 58 bearing against the pin oi' link 60.

This movement of the link draws the plate member 40 down with it against the resultant pressure of the springs 52 and 38, thus opening the circuit.

It is thus apparent that not until the pressure in the pressure chamber 16 has reached a value below that of the resultant pressure of the two springs 38 and 52 will these springs be able to force the bridge member 54 upwardly to form a contact with the contact members 48 and thus close the circuit to operate the compressor. This provides a dennite, predetermined range of preslures within which the switch will not close for the purpose of permitting the compressor to function. This will be the useful range of pressures within whichthe pressure in the storage tank is sumcient to carry out the purposes for which it was designed.

Furthermore, by simply shifting the relative position of the camming slot 58 in the outer end of the rocker arm 30, less pressure will be required to withdraw the bridge member 58 from the contact members 48 and in this way the particular range of useful operating pressures may be predetermined prior to assembling the switch. In other'words, rocker members containing varinus shaped slots may be assembled with all of the other standard parts, thus necessitating the manufacture in other than standard manner' of but one part of this assembly.

Variousmodiflcations of my device will be apparent to those skilled in the art, and for that reason I intend to limit myself only within the scope of the appended claims.

I claim:-

1. An electric switch comprising a hollow body member having a central aperture in its top, a contact member including a flanged stem axially slidable through said aperture, a plate supporting the lower extremity of said stem, a coiled spring thereabout seated upon the flange of said stem and bearing against the underside of said top, a second spring supporting said platel a pressure sensitive diaphragm, and operative connections between said plate and diaphragm.

2...Mechanism for expanding and compressing a coil spring in response to a force variation coaxial therewith comprising plates positioned against the opposite ends of said coil spring, one of said plates being free to move with one end of the spring and the other plate constituting a relatively fixed abutment for the other end of the spring, a rocker arm pivoted about a point fixed with reference to said abutment plate, a link connecting one end of the rocker arm and the movable plate, and a member movable coaxially with said spring in response to force exerted therein coupled with the opposite end of the rocker arm. Y

3. Mechanism of the described class comprising a fixed plate, a coil spring seated thereon, a plate oatingly supported upon the opposite end of said spring, a member movable axially with reference to said spring slidably positioned below said fixed plate, a rocker arm pivoted about a xed point adjacent said axially movable member and having one arm engageable therewith. and a link connecting the other end of said rocker arm with the fioatingly supported plate.

4. Switch mechanism of the class described comprising a casing, a coil spring therein, a plate arranged at each end of the spring, rocker mechanism operable to urge one of said plates to compress the spring, a link slidably coupled with said rocker mechanism and connected with the plate at the opposite end of the spring operable upon movement of said rocker mechanism against the first plate to compress the spring to simultaneously urge the other plate in the opposite direction against the tension of the spring, and a switch contact carried by said second plate.

VINCENT G. APPLE. 

